New gear review and problem solving

Introduction

Over the last several months, Biokryptos project Tepui Watch entered phase three, camera trapping in uncharted parts of Auyan Tepui. We have had a great deal of success, with news images and confirmed captures of a variety of animals previously undocumented on any tepui summit. However, we have had a variety of difficulties including false captures, potential sampling biases, equipment loss and limited field time. We have also missed a meaningful segment of the faunal composition of Auyan; the herpetofauna. In order to address these deficiencies in our methods, we at Biokryptos have added new gear which will be field tested and evaluated for future use, and adopted some new methodologies for surveying fauna in unexplored portions of the tepui

Camera Traps

The first new piece of gear we are going to test is the Moultrie 180i one hundred and eighty degree panoramic camera trap. Manufactured by Moultrie inc, this camera is unusual in that it can provide an approximate 180 degree view using three separate cameras and three infrared motion sensors. It is unique in that it does not use mechanical moving components like their previous 155 panoramic camera. I chose this model for its advanced 180 degree view, and the improvements in this technology since the advent of panoramic camera traps. I intend to place this camera in the lagoon area to monitor the shores and inlets of the lagoon. Ideally, I would have three such cameras to monitor all inlets and outlets, but the current budget is tight and I want to test the model before using it.

Our camera traps have so far been comprised of models from three companies: Moultrie, Bushnell, and Reconyx . As of the last data retrieval, the most useful captures have come from the Bushnell cameras, although the highest resolution images come from Reconyx. As we started this project with a single Moultrie camera (Biokryptos 1, which is still operational) I want to determine if Moultrie has improved its infrared triggers, resolution, or camera capabilities. We will see if this model lives up to its advertising, and if it can handle the rigors of a tepui environment.

180i by Moultrie. 

Baiting system

One major issue confronting our camera trap study on Auyan is the number of recaptures of Didelphis imperfecta , a Venezuelan opossum and endemic of the Guiana Shield. There were hundreds of photos of these animals recorded, enough to indicate that we may be looking at sampling bias. One major cause of this may be the type of bait we were using: suet cake. The suet cake we chose was a cooked peanut based variety, to avoid spreading unwanted seeds on the tepui. With all cooked peanuts, we have no chance of spreading invasives on the tepui. However, this type of bait is irresistible to possums and rodents, and the continued presence of these animals biased the capture zone against other large mammals, and reptiles (birds seemed unaffected).  Equally, the camera traps have been unsuccessful at photographing herpetofauna, with the exception of a large snake in Naranja. Our solution to this problem is for the moment three approaches:

1) Bait alteration

We have switched away from suet cake to cooked vegetables: bananas, and potato skins, effervescent local vegetables. This is the bait which attracted the crab eating fox in Guayaraca during the pilot study (link to crab eating fox). With a lower protein content, this new bait should prevent capture bias in favor of rodents and opossums.

Trader Joes always has odoriferous dried fruit at a good price

2) Attractive baits

For certain animals, particularly actively hunting reptiles and gregarious mammals, an odoriferous bait may be ignored. So, instead of using food, we will be experimenting with a moving bait. I have chosen to use an artificial moving butterfly as a trial bait source. hopefully, the novelty aspect and movement of this lure will attract different varieties of animals which the camera traps have missed.

a simple set up, but untested to my knowledge

We are also going to try something more unorthodox in the lagoon area. During the initial explorations at the site, Arturo photographed what he believes to be claw marks on trees produced by jaguars or other big cats. There have been reports of big cats on Auyan in the past (National Geographic, May, 1989), and obtaining photographic evidence of one would alter our understanding of tepui invasives, and the ecosystem diversity of Auyan Tepui itself. To facilitate this process, I have obtained Calvin Klein's Obsession for men to use as a jaguar attractant. Apparently, the civetone extract from civets attracts big cats to camera traps. This system has been used before, and I intend to test its effectiveness in an area with evidence of big cats.

Labeled attractant to prevent any confusion

3) Camera trap layout

So far, we have attempted to use the cameras in pairs, and have placed them in natural cul de sacs so as to funnel animals into the capture zone. This time, we will attempt to clear out a capture zone instead, and focus on locating game trails, and along shore lines near the rivers. We will also attempt to secure images of reptiles by using cork board to capture images of small reptiles.

It is notoriously difficult to capture images of small reptiles on camera traps, due to their relatively negligible thermal signature. However, a method exists, as outlined by Dustin Welbourn in the Herpetological Review 2013. In this case, we will place a camera trap near a natural funnel and a sheet of cork board down to boost the infrared signal produced by the reptile passing over the cork. Hopefully, this method will allow us to at least partly survey the reptiles of Auyan.

Field Gear

As stated before, we encountered a series of difficulties in field surveying due to a lack of equipment. The obvious solution was to obtain new equipment which we missed, in this case that is camera equipment, GPS navigation devices, and power charging stations. These devices, in combination with a larger amount of camping foodstuffs, should solve the majority of problems we encountered in the past.

For the camera equipment, we chose to use the GoPro Hero which was used during the 2014 expedition. The GoPro camera system has proven its worth in the difficult tepui environment, and is light weight enough that it can be packed and used without additional difficulty for the Pemon investigators. The only drawback at the moment is that it does not come with an adequate microphone, and in the future a proper microphone for documentary production will need to be obtained.

Next, we obtained a Garmin eTrex 10 series handheld GPS device. This system is very affordable, around $100. It boasts the ability to use GPX files so we can create routes and load them directly to the device, instead of inputting them from Google Earth manually. According to the manufacturers, it has the ability to keep position in dense forests and deep canyons, with WAAS enabled receivers and HotFix satellite prediction, Finally, it uses GPS and GLONASS satellite, so it should work more quickly than our previous GPS devices, with access to additional satellites. We will see how this device holds up to what it promises on Auyan, in the dense jungle in the north of the tepui.

For food prep needs, I have used a MSR DragonFly backpacking stove. The beauty of this system, beside its light weight and durability, is that it can utilize a variety of fuel sources including automotive gasoline to cook. This is a tremendous help in a country where gasoline is subsidized, but propane may be hard to find.


Finally, I have a Lighthouse 400 lantern and USB portable hub manufactured by Goal Zero, makers of solar and environmentally friendly outdoor adventure products. This system is hand cranked, and can generate enough power to theoretically charge a variety of our devices, including the GoPro camera as well as cell phones and devices. We will see what our lead investigator Arturo thinks about this charging station/lantern, and what kind of power it can generate for mobile devices.

Goal Zero lantern

Conclusion: gear reviews and testing new approaches.

The gear updates represents an acceleration in our efforts on Auyan. It is a tremendous amount of new equipment, and will be combined with shipments of spotting scopes, more camera traps, and additional scientific equipment. We have not yet begun to address a variety of new approaches in remote monitoring, including environmental DNA analysis or atmospheric gas monitoring. As such, we will be conducting two expeditions in short order: one to Lecho and Dragon for herpetological surveying, and a return to the lagoon and north of Auyan to service our camera traps. The results of our gear performance will be known by fall 2017.